Liquid fuel pumping apparatus for internal combustion engines



April 20, 1965 P. E. GLIKIN 3, 7 1

LIQUID FUEL PUMPING APPARATUS,FOR INTERNAL COMBUSTION ENGINES Filed Feb.14, 1964 r 764 W 2 t 1 22b /63 2 Claims. (Cl. 123-139) This inventionrelates to liquid fuel pumping apparatus for internal combustionengines, and of the kind comprising in combination a rotary distributoradapted to be driven by the engine, a head at one end of the distributorsaid head having therein a bore, at least one plunger in the bore, afeed pump for feeding fuel intermittently as the distributor rotates, ata pressure dependent on the speed of the engine, to the bore in the headso as to move the plunger outwardly, a metering valve for controllingthe supply of fuel from the feed pump to the bore, a cam for impartinginward movement to the plunger as the head rotates, and thereby deliverfuel through the distributor to the engine cylinders in turn and a fluidoperable piston contained in a timing cylinder and for imparting angularmovements to the cam to vary the timing of the delivery of fuel to theengine.

The object of this invention is to provide such a pump in an improvedform.

According to the invention a liquid fuel pumping apparatus of the kindspecified is characterised in that one end of the timing cylinder isconnected to a point downstream of a restriction disposed intermediatethe feed pump and the metering valve, only during the time when fuel isbeing supplied to the bore, so that the pressure of fuel applied to thecylinder is dependent upon the rate of flow of fuel through the meteringvalve and therefore upon the speed of, and load on, the engine withwhich the apparatus is associated.

in the accompanying drawings:

FIGURE 1 is a sectional side elevation of one example of a liquid fuelpumping apparatus in accordance with the invention,

FIGURE 2 is a section on the line 2-2 of FIGURE 1,

FIGURE 3 is a section on the line 3-3 of FIGURE 1 and FIGURE 4 is a viewsimilar to FIGURE 2 showing a modification.

Referring to the drawings there is provided a body part 1 in which ismounted a rotary distributor 2 adapted to be driven in timedrelationship with the engine with which the pumping apparatus isassociated. Formed on one end of the distributor is a head 3 havingtherein a transverse bore 4 whilst on the other end of the distributoris mounted a feed pump 5, conveniently of the vane type, having a fuelinlet 6 and a fuel outlet '7 in the body part and arranged to deliverfuel at a pressure dependent on the speed of rotation thereof by meansof a regulating valve interconnecting the inlet and the outlet. Theregulating valve includes a spring loaded valve member 8 which, as shownin FIGURE 1, is able to close a passage 8* interconnecting the outlet 7and inlet 6 of the feed pump. As the flow through the passage 3*increases (as the speed of rotation of the feed pump increases) thevalve member will be lifted and the pressure at the outlet will increasebecause the spring has to be compressed more. Thus the pressure at theoutlet of the pump is dependent upon the speed of the engine. It shouldbe noted that the feed pump is arranged to deliver a much greaterquantity of fuel than is required by the engine so that there is alwaysfuel flowing in the passage S even when the engine is being cranked forstarting purposes. Within the transverse bore is a pair of plungers 9and piston.

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fuel is fed to the space between the plungers, to move the latteroutwardly, through a longitudinal. passage 14) in the distributor. Fuelis fed to this passage, through one of four equi-angularly spaced radialinlet passages 11 which at their inner ends are in communication withthe longitudinal passage 10 and which at their outer ends, register inturn as the distributor rotates with an inlet port 12 in the body part.The inlet port 12 communicates with the outlet port 7 of the feed pumpvia a retricted orifice 13 contained in a longitudinal passage in thebody part and a metering valve 14 arranged in series and the arrangementis such that when the inlet port 12 is in register with one of the inletpassages 11 a controlled quantity of fuel will be delivered to thetransverse bore 4 to move the plungers 9 outwardly. I

The plungers 9 are moved inwardly, during at least a portion of the timewhen the inlet port 12 is out of register with one of the inlet passages11, by the action of an annular cam 15, surrounding the head 3, and thelobes of which act on the plungers through a pair of rollers 16 disposedbetween the plungers 9 and the cam 15 respectively. The fuel displacedfrom the transverse bore by the plungers is delivered via thelongitudinal passage 10 to a radial delivery passage 17 which registersin turn, as the distributor rotates, with one of four equi-angularlyspaced delivery ports 18 in communication with the cylinders of theengine respectively.

In order to vary the timing of injection of fuel into the enginecylinders the annular cam is angularly movable by a fluid operablespring loaded piston 19 which is contained within a cylinder 20 the axisof which is parallel to a tangent to the annular cam 15. Fluid pressureis applied to the end of the cylinder 20 remote from the spring onlyduring the time when fuel is being delivered to the transverse bore,this being achieved through one of four equi-angularly spaced recesses21 formed in the periphery of the distributor which communicate with apoint intermediate the orifice 13 and the metering valve 14 and whichare arranged to register in turn with a port 22 which is incommunication through conduit 22 with said end of the cylinder. Thearrangement is such that the locked off quantity of fuel in the cylinder20 will resist the torque applied to the annular cam 15 by the plungers9. Moreover since the flow through the orifice 13, and hence thepressure downstream thereof, is determined by the setting of themetering valve 14, the timing of the injection will be determined by theload on, and the speed of, the engine. The load on an engine at a steadyspeed is the same as the torque developed by the engine and it is knownthat in normal operating conditions the rate at which fuel is deliveredto an engine is roughly proportional to the torque developed by theengine.

In a modification, illustrated in FIGURE 4 of the drawings, the piston23 which moves the cam 15 is of stepped form and is mounted in a steppedcylinder 24 the narrower end of which contains the spring acting on theThe wider end of the cylinder is intermittently supplied with fuel byway of the port 22 and conduit 22*, and the narrower end of the cylinderis supplied with fuel from a point upstream of the orifice 13 throughconduit 22*. By this means the effect of speed, as compared to theeffect of load, on the amount of movement imparted to the cam isreduced.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. Liquid fuel pumping apparatus for supplying fuel to internalcombustion engines and comprising, in combination, a body part, a rotarydistributor adapted to be driven in timed relationship to an engine withwhich the apparatus is associated, a bore defined in the distributor, aplunger slidable in said bore, a delivery passage in the distributor, aplurality of outlet ports in the body part s; 7 arranged to be incommunication with the engine cylinders respectively, and with which thedelivery passage registers in turn, a cam for imparting inward movementsto the plunger as the distributor rotates, said inward movement of theplunger taking place whilst the delivery passage is in communicationwith an outlet port, a feed pump mounted in the body part and arrangedto'be driven by the distributor, said feed pump having an inlet and anoutlet, a relief valve for controlling the output pressure of the feedpump in a manner such that the pressure is dependent upon the speedofrotation or" the distributor, a'plurality of inlet passages formed inthe distributor and communicating with said bore, an inlet port in thebody part and with which the inlet passages register in turn as thedistributor rotates, passage means in the body part serving tointerconnect the output of the feed pump with said inlet port, saidinlet port being arranged to register with an inlet passage so as toallow fuel to flow to the bore to move the plunger outwardly during thetime when the delivery passage is out of register with an outlet port, acylinder defined in the body part, a fluid operable piston mountedwithin the cylinder, means interconnecting the piston and said cam sothat as the piston is moved the cam will be moved to vary the instant atwhich the plunger is moved inwardly, a metering valve mounted in said 7passage means for controlling the quantity of fuel delivered by the feedpump to the bore, a restriction located in said passage meansintermediate the feed pump outlet and the metering valve, conduit meansinterconnecting a point in said passage means intermediate the meteringvalve and the restriction with one end of said cylinder, resilient meansaccommodated in said cylinder for opposing the movement of the piston bythe fuel pressure flowing through said conduit means, and rotary valvemeans for controlling the ilow of fuel through said conduit 2. Liquidfuelpumping apparatus for supplying fuel to internal combustion enginesand comprising, in combination, a bodypart, a rotary distributor adaptedto be driven in timed relationship to an engine with which the apparatusis associated, a bore defined in the distributor, a plunger slidable insaid here, a delivery passage in the distributor, a plurality of outletports in the body part arranged to be in communication with the enginecylinders respectively, and with which the delivery passage registers inturn, a cam for imparting inward movements to the plunger as thedistributor rotates, said inward movement or" the piunger taking placewhilst the delivery passage is in communication with an outlet port, afeed pump mounted in the body part and arranged to be driven by thedistributor, said feed pump having an inlet and an outlet, a reliefvalve for controlling the output pressure of the feed pump in a mannersuch that the pressure is dependent upon the speed of rotation of thedistributor, a plurality of inlet passages formed in the distributor andcommanicatinz with said bore, an inlet port in the body part and withwhich the inlet passages register in turn as the distributor rotates,passage means in the body part serving to interconnect the output of thefeed pump with said inlet port, said inlet port being arranged toregister with an inlet passage so as to allow fuel to flow to the boreto move the plunger outwardly during the time when the delivery passageis out of register with an outlet port, a stepped cylinder defined inthe body'part, a stepped fluid operable piston occupying said steppedcylinder, means interconnecting said piston and the cam, so that as thepiston is moved the cam will be moved to vary the instant at which theplunger is moved inwardly, a metering valve mounted in said passagemeans for controlling the quantity of fuel delivered by the feed pump tothe bore, a restriction located in said passage means intermediate thefeed pump outlet and the metering valve, first conduit meansinterconnecting a point in said passage means intermediate the meteringvalve and the restriction with the wider end of said cylinder, secondconduit means interconnecting the outlet of the feed pump with thenarrower end of said stepped cylinder, resilient meansaccommodatedwithin said stepped cylinder for opposing the movementof thestepped piston towards said narrower end of the cylinder, and rotaryvalve means for controlling the flow of fuel through said first conduitmeans.

FOREIGN PATENTS 10/57 Great Britain.

RICHARD B. WILKINSON, Primary Examiner.

1. LIQUID FUEL PUMPING APPARATUS FOR SUPPLYING FUEL TO INTERNALCOMBUSTION ENGINES AND COMPRISING, IN COMBINATION, A BODY PART, A ROTARYDISTRIBUTOR ADAPTED TO BE DRIVEN IN TIMED RELATIONSHIP TO AN ENGINE WITHWHICH THE APPARATUS IS ASSOCIATED, A BORE DEFINED IN THE DISTRIBUTOR, APLUNGER SLIDABLE IN SAID BORE, A DELIVERY PASSAGE IN THE DISTRIBUTOR, APLURALITY OF OUTLET PORTS IN THE BODY PART ARRANGED TO BE INCOMMUNICATION WITH THE ENGINE CYLINDERS RESPECTIVELY, AND WITH WHICH THEDELIVERY PASSAGE REGISTERS IN TURN, A CAM FOR IMPARTING INWARD MOVEMENTSTO THE PLUNGER AS THE DISTRIBUTOR ROTATES, SAID INWARD MOVEMENT OF THEPLUNGER TAKING PLACE WHILST THE DELIVERY PASSAGE IS IN COMMUNICATIONWITH AN OUTLET PORT, A FEED PUMP MOUNTED IN THE BODY PART AND ARRANGEDTO BE DRIVEN BY THE DISTRIBUTOR, SAID FEED PUMP HAVING AN INLET AND ANOUTLET, A RELIEF VALVE FOR CONTROLLING THE OUTPUT PRESSURE OF THE FEEDPUMP IN A MANNER SUCH THAT THE PRESSURE IS DEPENDENT UPON THE SPEED OFROTATION OF THE DISTRIBUTOR, A PLURALITY OF INLET PASSAGES FORMED IN THEDISTRIBUTOR AND COMMUNICATING WITH SAID BORE, AN INLET PORT IN THE BODYPART AND WITH WHICH THE INLET PASSAGES REGISTER IN TURN AS THEDISTRIBUTOR ROTATES, PASSAGE MEANS IN THE BODY PART SERVING TOINTERCONNECT THE OUTPUT OF THE FEED PUMP WITH SAID INLET PORT, SAIDINLET PORT BEING ARRANGED TO REGISTER